Index: include/utils/SkRandom.h |
diff --git a/include/utils/SkRandom.h b/include/utils/SkRandom.h |
index d083fc6b2f358d8911af9ee5331e20c2b050dc1d..aee2d7a0aaef057d03f557ccada28b1f7ad8fa96 100644 |
--- a/include/utils/SkRandom.h |
+++ b/include/utils/SkRandom.h |
@@ -10,145 +10,6 @@ |
#include "SkScalar.h" |
-/** \class SkLCGRandom |
- |
- Utility class that implements pseudo random 32bit numbers using a fast |
- linear equation. Unlike rand(), this class holds its own seed (initially |
- set to 0), so that multiple instances can be used with no side-effects. |
-*/ |
-class SkLCGRandom { |
-public: |
- SkLCGRandom() : fSeed(0) {} |
- SkLCGRandom(uint32_t seed) : fSeed(seed) {} |
- |
- /** Return the next pseudo random number as an unsigned 32bit value. |
- */ |
- uint32_t nextU() { uint32_t r = fSeed * kMul + kAdd; fSeed = r; return r; } |
- |
- /** Return the next pseudo random number as a signed 32bit value. |
- */ |
- int32_t nextS() { return (int32_t)this->nextU(); } |
- |
- /** Return the next pseudo random number as an unsigned 16bit value. |
- */ |
- U16CPU nextU16() { return this->nextU() >> 16; } |
- |
- /** Return the next pseudo random number as a signed 16bit value. |
- */ |
- S16CPU nextS16() { return this->nextS() >> 16; } |
- |
- /** |
- * Returns value [0...1) as a float |
- */ |
- float nextF() { |
- // const is 1 / (2^32 - 1) |
- return (float)(this->nextU() * 2.32830644e-10); |
- } |
- |
- /** |
- * Returns value [min...max) as a float |
- */ |
- float nextRangeF(float min, float max) { |
- return min + this->nextF() * (max - min); |
- } |
- |
- /** Return the next pseudo random number, as an unsigned value of |
- at most bitCount bits. |
- @param bitCount The maximum number of bits to be returned |
- */ |
- uint32_t nextBits(unsigned bitCount) { |
- SkASSERT(bitCount > 0 && bitCount <= 32); |
- return this->nextU() >> (32 - bitCount); |
- } |
- |
- /** Return the next pseudo random unsigned number, mapped to lie within |
- [min, max] inclusive. |
- */ |
- uint32_t nextRangeU(uint32_t min, uint32_t max) { |
- SkASSERT(min <= max); |
- uint32_t range = max - min + 1; |
- if (0 == range) { |
- return this->nextU(); |
- } else { |
- return min + this->nextU() % range; |
- } |
- } |
- |
- /** Return the next pseudo random unsigned number, mapped to lie within |
- [0, count). |
- */ |
- uint32_t nextULessThan(uint32_t count) { |
- SkASSERT(count > 0); |
- return this->nextRangeU(0, count - 1); |
- } |
- |
- /** Return the next pseudo random number expressed as an unsigned SkFixed |
- in the range [0..SK_Fixed1). |
- */ |
- SkFixed nextUFixed1() { return this->nextU() >> 16; } |
- |
- /** Return the next pseudo random number expressed as a signed SkFixed |
- in the range (-SK_Fixed1..SK_Fixed1). |
- */ |
- SkFixed nextSFixed1() { return this->nextS() >> 15; } |
- |
- /** Return the next pseudo random number expressed as a SkScalar |
- in the range [0..SK_Scalar1). |
- */ |
- SkScalar nextUScalar1() { return SkFixedToScalar(this->nextUFixed1()); } |
- |
- /** Return the next pseudo random number expressed as a SkScalar |
- in the range [min..max). |
- */ |
- SkScalar nextRangeScalar(SkScalar min, SkScalar max) { |
- return this->nextUScalar1() * (max - min) + min; |
- } |
- |
- /** Return the next pseudo random number expressed as a SkScalar |
- in the range (-SK_Scalar1..SK_Scalar1). |
- */ |
- SkScalar nextSScalar1() { return SkFixedToScalar(this->nextSFixed1()); } |
- |
- /** Return the next pseudo random number as a bool. |
- */ |
- bool nextBool() { return this->nextU() >= 0x80000000; } |
- |
- /** A biased version of nextBool(). |
- */ |
- bool nextBiasedBool(SkScalar fractionTrue) { |
- SkASSERT(fractionTrue >= 0 && fractionTrue <= SK_Scalar1); |
- return this->nextUScalar1() <= fractionTrue; |
- } |
- |
- /** |
- * Return the next pseudo random number as a signed 64bit value. |
- */ |
- int64_t next64() { |
- int64_t hi = this->nextS(); |
- return (hi << 32) | this->nextU(); |
- } |
- |
- /** |
- * Return the current seed. This allows the caller to later reset to the |
- * same seed (using setSeed) so it can generate the same sequence. |
- */ |
- int32_t getSeed() const { return fSeed; } |
- |
- /** Set the seed of the random object. The seed is initialized to 0 when the |
- object is first created, and is updated each time the next pseudo random |
- number is requested. |
- */ |
- void setSeed(int32_t seed) { fSeed = (uint32_t)seed; } |
- |
-private: |
- // See "Numerical Recipes in C", 1992 page 284 for these constants |
- enum { |
- kMul = 1664525, |
- kAdd = 1013904223 |
- }; |
- uint32_t fSeed; |
-}; |
- |
/** \class SkRandom |
Utility class that implements pseudo random 32bit numbers using Marsaglia's |